Load bearing acoustic building block



M. T. STRAIGHT Filed Aug. 25, 1959 LOAD BEARING ACOUSTIC BUILDING BLOCK April 28, 1942.

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Patented Apr. 28, 1942 UNITED STATES PATENT OFFICE 2,281,121 LOAD BEARING acousnc BUILDING BLOCK Merton '1. Straight, Des Memes, Iowa Application August 25, 1939, Serial No. 291,887

5 Claims.

The object of my invention is to provide an improved building block formed of plastic material having all of the properties of the vitrified building block as to strength, appearance and density, and provided with sound absorbing properties, whereby the block may be used to construct; the interior of walls and partitions of auditoriums by being laid in mortar or cement in the usual manner, and when so laid will absorb and diffuse audible sound waves striking said wall or partition to prevent reflection of the same to such an extent that undesirable echoes may be eliminated within the room or building formed of said blocks without the application of independent sound absorbing material.

A further object of my invention is to provide in a load-bearing building block having acoustic properties, of such size and shape that it may be laid in conjunction with transparent and ornamental blocks of standard shape and size to provide ornamental as well as acoustic effects without any additional decoration, and yet so constructed that decorative substance such as paint or the like may be readily applied if so desired.

A further object of my invention is to provide a load-bearing building block of plastic material which may be made by methods and machinery such as now in common use in the manufacture of ordinary load-bearing building blocks.

My invention consists in the construction, arrangement and combination of the various parts of the device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawing, in which:

Figure 1 is a perspective view of one form of my improved acoustic block;

Figure 2 is an end elevation of same;

Figure 3 is a side elevation of my improved block;

Figure 4 is an enlarged detail sectional view showing the manner in which the ends of my improved block are secured together by mortar, and the manner in which the cavities therein are sealed at their ends;

Figure 5 is an end elevation of a modified form of my improved block;

Figure 6 is an enlarged detail sectional view illustrating another modified form of my improved acoustic block.

My improved block consists of -a body l formed of plastic material, having side members ll, edges l2 and ends ii. The body is provided with rows of longitudinal cavities i4 and I formed in the plastic body by suitable dies, in the ordinary manner, such as used in the construction of the ordinary plastic building block, the cavities I being formed in horizontal an angle of incidence.

45 no additional breaking up or absorption of the sound wave is rows aboveand below a partition it, the outer sides of the cavities I! being provided with out wardly inclined faces I 1. The cavities I5 are arranged in rows between the rows l4 and the 5 corresponding faces ll of said body, said cavities being formed in staggered relation to the cavities I 4, as clearly illustrated in Figure 2 of the drawings, the inner side of the cavities I5 having inclined portions l8 diverging inwardly and 10 substantially parallel with the inclined portions II, the outer surfaces of the cavities l5 being preferably somewhat arched as at It. The inclined walls I! and iii are spaced apart such a distance that partitions are provided and so in proportioned with relation to the partition I6 and the side walls that the plastic body will flow uniformly through a die of the type ordinarily used in the manufacture of plastic building blocks. The outer surfaces of the sides and 20 edges of the body are roughened by scratching said surfaces longitudinally as the plastic column is conveyed from the die to the cut-off table to form irregular grooves 2i which are of such depth and of such distance apart that the material between the grooves will not be pulled or symmetrical formation of grooves and ridges,

thus providing a surface that is not only ornamental but also very efficient in the breaking up of sound waves to prevent said waves being refiected in a definite direction in respect to their In other words, to provide a surface that will reflect the sound wave of a given angle of incidence in a large number of directions in respect to their angle of incidence in a more or less diffused manner. This roughened surface also provides means for absorbing some of the sound energy through friction and heat resulting therefrom. The roughened surface also provides a very ornamental surface that is pleasing to the sight, and usually requires ornamentatiom further enhanced by passages 23 and 24 which are formed in the walls of the body, said passages having their inner ends connecting with said cavities i4 and I5, and their outer ends terminating in said roughened surface, as clearly illustrated in Figure 2, said passages 23 and 24 being arranged either symmetrically or in a non-symmetrical manner as to their distance of spacing one relative to another.

In the construction of wall formed from'my improved blocks the ends of the blocks and two of their sides or edges are laid in mortar in the usual manner.

so In Figure 5 I have illustrated a somewhat modi- The further square in cross section, having comparatively large longitudinally extending cavities 25 and partitions 26. Between the cavities 25 and the corresponding outer surfaces of the body I have provided two rows of cavities 21 and 28, these cavities 21 and 28 being provided with laterally extending passages 28, having their outer ends terminating in the roughened outer surface of said body.

In Figure 6 I have illustrated another modified form of block in which the cavities l4 and I! are filled with a quantity of particles of material ill, such as sawdust or expanded mica flakes, to form a sound absorbing filter, and retained within the cavities and bound together by a suitable binder such as Portland cement or water-proofing glue, the filter being placed within the cavities of the block after the block has been hardened by drying, or by burning and vitrification, and firmly retainedtherein by the said binder so that the block may be handled and transported from one point to another. This filter provides means whereby under certain conditions the soundabsorbing qualities may be increased, or, under other conditions, part of the cavities l4 and I! may be filled with the filter and others left empty,

thus providing means whereby the resonant peak of the sound reflected waves of the block may be greatly broadened.

Thus, it will be seen I have provided a loadbearing building block which is constructedof a hard refractory material and capable of being laid in the partition walls of a building .or in the exterior walls, and to carry a superimposed load, and at the same time have provided a block having ornamental exposed surfaces and one in which a large percentage of the sound wave striking the roughened surface ofthe block will be reflected and diffused in various directions so that at no time will a given sound wave have its entire energy focused at any particular point in the building. A large percentage of the energy is also absorbed by friction in the walls of the longitudinal cavities. I have also provided'an improved acoustic block which may be manufactured by the ordinary machinery used in the manufacture of plastic wall blocks, with the addition of mechanism for perforating the sides of the walls, the blocks thus formed being burned in the usual manner.

It will further be seen that I have provided a building block having two of its surfaces roughened, and opposite said roughened surfaces, longitudinal cavities with a partition between said cavities formed integrally as a part of the body,

and passages extending between the roughened surfaces and the corresponding cavities so that each side of the block is provided with an acoustic construction, one of which is independent of the other as providedin the central partition, so that sound waves entering the passages of one surface will not be transmitted through the passages of the other surface, thus providing a block which is formed integrally therewith with each of its opposite sides so constructed'as to have acoustic properties without having to attach to the surface of the wall additional soundabsorbing devices such. as are now in quite common practice. 7

I claim as my invention:

1. An improved load-bearing building block formed of plastic material having two of its side faces roughened to form an irregular and uneven surface, a'cavity extending longitudinally through said block opposite each of said roughened surfaces, and a partition impervious to the passage of sound vibrations between said cavities formed integrally with said body, said roughened surfaces being provided with inwardly projecting passages having their inner ends connected with said cavities;

2. An improved refractory load-bearing building block, comprising a hollow body having a central and longitudinally extending Partition impervious to the passage of sound vibrations and its outer surface opposite said partition being provided with very irregular and non-uniformly arranged grooves to form surfaces capable of re flecting portions of sound waves striking said surfaces at various angles relative to their angle of incident,'and a plurality of comparatively narrow and laterally formed passages connecting said outer'surface and the corresponding cavities on opposite sides of said partition, whereby the building block may be laid in a partition wall,'in single tiers to provide sound-deadening surfaces and at the same time, to prevent sound waves from passing through said block from one surface to the other.

3. An improved load-bearing building block formed of plastic material, comprising a body having a plurality of longitudinal rows of cavities on opposite sides of a central partition forming an integral portion of said body, the cavities of one row of cavities being larger and staggered in relation to those of another row of cavities, the side faces of said body opposite the rows of said cavities being roughened and provided with a plurality of comparatively narrow and laterally formed passages connecting the roughened, outer surface and the outer walls of said cavities, said cavities being taggered so that all of said laterally formed passages will have their inner ends terminating in one or the other of saidcavities, for the purpose of forming resonant chambers of different sizes whereby the resonant peak of the block may be broadened. i I

4. An improved load bearing building block formed of plastic material, comprising a body having spaced longitudinal cavities to form a unitary partition impervious to the passage of sound vibrations between them, the sides of said block opposite said cavities having a sound-diflusing and absorbing surface, including passages connecting said cavities and said surfaces, said partitions serving to prevent passage of sound waves from one sound-absorptive surface to the other when the blocks are laid in a partition wall and I in a single tier.

' 5. An improved load-bearing building block formed of plastic material, comprising a body having a plurality of longitudinal rows of cavities, the cavities of one row of cavities being larger and staggered in relation to those of another row. of cavities, the side faces, of said body opposite the rows of said cavities being roughened and provided with a plurality of comparatively narrow and laterally formed passages connecting a the roughened outer surface and the outer walls of said cavities, said cavities being staggered so that all of said laterally formed passages will have their inner ends terminating in one orv the other of said cavities, for the purpose of forming resonant chambers of different sizes whereby the resonant peak of the block may be broadened.

DEERTON T. STRAIGHT. 

